No. 2, November, 1920] PHYSIOLOGY 123 



ORGANISM AS A WHOLE 



S")S. Mkadbb, 1'. I)., AND G. II. RoBINSON. Some physical and biological properties of the 

 streptococcus hemotoxin. [Abstract.] Absts. Bact. 4: 17. L920. 



859. l'mxiisiiioiM, Hans. Symbiose bei Bakteria. [Symbiosis of bacteria.] Naturwissen- 

 schaften 8: 101-103. 1920. 



SCO. W[inslow], C.-E. A. The lactic acid bacteria. [Rev. of : Obxa-Jensen, S, The lac- 

 tic acid bacteria. Mem. Acad. R. Sci. et Let. Danemark (Sect. Sci.) VIII, 5: 81-196. 51 pi, 

 1919.] Absts. Bact. 4: 102. 1920.— See Bot. Absts. 6, Entry 183. 



GROWTH, DEVELOPMENT, REPRODUCTION 



861. CorjpiN, H. Sur les causes de lelongation de la tige des plantes etiolees. [The causes 

 of stem elongation in etiolated plants.] Gompt. Rend. Acad. Sci. Paris 170: 189-191. 1920. — 

 In a study of etiolation in seedlings of white lupine it is found that the rate and the total 

 amount of elongation of the hypocotyls and the roots of plants growing in the dark may be 

 prevented from materially exceeding that of seedlings grown in light, if there is added to the 

 media in which the seedlings are grown a quantity of the expressed sap of seedlings grown in 

 light. It is therefore concluded that chloroplasts in the presence of light produce a substance 

 which though not entirely toxic has a retarding effect upon the rate of growth. Thus the ex- 

 pressed sap of green seedlings reduces the rate of growth of plants growing in darkness, whereas 

 in plants grown in darkness in water or in a solution containing the expressed sap of etio- 

 lated plants the ordinary rapid elongation characteristic of etiolation takes place. — C. H. & 

 W. K. Fair. 



862. Marshall, Max Skidmore. Association of Bacillus subtilis and Streptococcus 

 lacticus. [Abstract.] Absts. Bact. 4: 5. 1920. 



863. Mitscherlich, E. A. Das Liebigsche Gesetz vom Minimum und das Wirkungs- 

 gesetz der Wachstumfactoren. [Liebig's Law of the Minimum and the "effect rule" of growth 

 factors.] Naturwissenschaften 8: 85-88. 1920. — Mitscherlich doubts the truth of Liebig's 

 Law, and he asks and attempts to answer the following questions: (1) Does the amount of 

 plant production depend on only one vegetation factor, the so-called minimum factor? (2) 

 According to what proportionality may this be true? He then formulates and illustrates with 

 curves the law of physiological relation, or better, the effect law of growth factors, and points 

 out that there can be no such thing as one minimum factor alone determining the amount of 

 plant production, but that all growth factors together have a very definite influence on pro- 

 duction. — Orton L. Clark. 



864. Molliard, M. Tuberisation aseptique de la carotte et du dahlia. [Tuber formation 

 of carrot and dahlia under aseptic conditions.] Compt. Rend. Soc. Biol. Paris 83: 138-140. 

 1920. — When grown free from bacteria or fungi carrots and dahlias formed their normal roots 

 or tubers, respectively, showing that the presence of a symbiotic fungus is not necessary 

 for this process. — E. A. Bcssey. 



865. Popoff, Methodi. Artificial parthenogenesis and cell stimulants. Sci. Amer. 

 Monthly 1: 312-316. 1 fig. 1920. [Translated from Biol. Centralbl. (Leipzig), April 20, 

 1916.] 



866. Urbain, A. Influence des matieres de reserve de l'albumen de la graine sur le devel- 

 oppement de l'embryon. [Influence of the reserve materials of the endosperm upon the devel- 

 opment of the embryo.] Rev. Gen. Bot. 32: 125-139, 165-191. U fig. 1920.— The author re- 

 ports notable success in rearing embryos which have been separated from their endosperms. 

 Several species were used, including wheat, oats, barley, Mirabilis jalapa, Daucus carota, 

 Nigdla hispanica, Spinacca oleracea and Pin-as pinea. — Experiments on wheat, oats, and 



